The disclosed polar sensor embodiments utilize rotating magnetic field concepts taken from Tesla Patent Nos. 381,968 May 1, 1888 382,279 May 1, 1888 382,280 May 1, 1888, 390,414 Oct. 2, 1888 390,721 Oct. 9, 1888.
It has been stated in Logue patent no. 5,754,043 col. 4, lines 39-42, a polar sensor driving core is "similar to poly-phase induction motor stator designs for generating rotating magnetic fields.".
Further it has been stated in the cited copending patent Ser. No. 09/023,516 page 1, last paragraph: "The present invention utilizes rotating field stator structure concepts originating with Tesla e.g. all poly-phase induction motor stator designs".
A dual driving core sensor was disclosed in the cited Logue patent no. 5,754,043 FIGS. 10, 11, col. 5, lines 1-67, and further in col. 6, lines 1-7, which had the capability of generating an "lactive flux helix" in the pick-up core in response to phasing differences between the two interacting driving fields.